Here is the full list of all 43 Mow Problem achievements.
Complete the tutorials
Complete the spring maps
Complete the summer maps
Complete the autumn maps
Unlock the lawn editor
Unlock the summer maps
Unlock the autumn maps
Launch a test map from the lawn editor
Complete 5 maps with 100%
Complete 10 maps with 100%
Complete 20 maps with 100%
Complete 33 maps with 100%
Find the mini golf course
Score a hole in one in mini golf
Mow 1,320,000 feet of lawn
Complete a map with a more than optimal command count
Complete a non-tutorial map without a grid or tape measure
Clear 100% coverage while only turning right
Complete a lawn with the flipped mowers mutator enabled
Complete a lawn with the reverse controls mutator enabled
Complete a lawn with the rainy day mutator enabled
Complete a lawn with the lucky rainbow mutator enabled
Complete a lawn with the Time Trial mutator enabled
Play through chapter one as Mum
Play through chapter one as daughter
Collect your first seeds
Collect all the seed varieties
Grow something in the greenhouse
Grow one of each plant in the greenhouse
Hit the panic button
Enter supervisor mode
Play the text adventure in supervisor mode
Cut back all the thorns in a single maze
Beat Larry in a race
Get a hole in one on the mini-golf course
Win a round of mini-golf
Complete a puzzle lock
Trim back 30 thorn bushes
Send 30 swarms of bees to sleep
Cycle 13 kilometres
Cycle 26 kilometres
Use all the phone boxes in a maze at least once
Check your mail at the terminal